The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 22, 1996
Filed:
May. 11, 1995
Applicant:
Inventors:
Robert L Zeller, III, Youngstown, NY (US);
David L Johnson, Williamsville, NY (US);
Assignee:
Other;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C01B / ;
U.S. Cl.
CPC ...
4235192 ; 423264 ; 423265 ; 423519 ;
Abstract
Disclosed is a method of manufacturing potassium sulfite from a potassium hydroxide feedstock. A feedstock is tested for the presence of iron and, if the feedstock contains less than 0.3 ppm of iron, it is reacted with sulfur dioxide in an aqueous solution to form potassium sulfite. Alternatively, potassium sulfite that has a yellow or brownish color can be decolorized by adding about 0.02 to about 0.8 wt % hypophosphorous acid to it.